Water Chiller Apparatus

ABSTRACT

The present subject matter provides chiller apparatus including a storage tank for storing the liquid and a refrigerant cooling system. The refrigerant cooling system includes a compressor attached to the storage tank, a condenser positioned downstream from the compressor to condense a refrigerant received therefrom, and at least one evaporator positioned downstream of the condenser and wrapped about the outer surface of the storage tank. The evaporator includes a negative pitch coil configured to direct refrigerant flow from a position near a top of the storage tank to a position near a bottom of the storage tank.

FIELD OF THE INVENTION

The present subject matter relates generally to water chillerapparatuses and appliances.

BACKGROUND OF THE INVENTION

Water chilling units have been adopted for wide range of commercial andresidential settings. Whether the need is for a precisely-chilledmedical imaging device, or an immediately-accessible supply of cooleddrinking water, water chillers have numerous potential uses. However,most existing water chillers are only available for large-scaleoperations. The high costs and/or large footprint of these existingmachines makes them unusable for many potential customers. Although someconventional systems may offer a large supply of pre-chilled water, manypotential users have neither the space nor resources needed to invest inthese conventional systems. Other conventional systems may require lessspace, but typically have little, if any, storage capacity forpre-chilled water.

In addition, the energy requirements for some such systems can be quitehigh. When the need for chilled water arises, users may be forced towait a considerable amount of time for water to reach the appropriatetemperature. If the stored amount of chilled water is minimal, the userwill risk quickly exhausting the chiller's supply. Even when rapidchilling is possible, conventional systems typically require a user toexpend large amounts of electrical power to quickly chill lukewarmwater. The delay and/or expense of using such systems makes theseconventional systems impractical for many potential uses and/or users.

As a result, there is a need for an efficient and inexpensive waterchiller that requires less space than conventional systems, while stillproviding an adequate amount of immediately-accessible pre-chilled waterstorage.

BRIEF DESCRIPTION OF THE INVENTION

The present disclosure relates, generally, to a chiller apparatusincluding a storage tank and a refrigerant cooling system. Therefrigerant cooling system includes a compressor, condenser, andevaporator attached to the storage tank to efficiently cool liquidtherein. Advantageously, the chiller apparatus may be smaller and lessexpensive to operate than conventional systems. Additional aspects andadvantages of the invention will be set forth in part in the followingdescription, or may be apparent from the description, or may be learnedthrough practice of the invention.

In one exemplary embodiment, a chiller apparatus for cooling a liquid isprovided. The chiller apparatus includes a storage tank for storing theliquid and a refrigerant cooling system. The storage tank has a top, abottom, and an outer surface. The refrigerant cooling system includes acompressor attached to the storage tank, a condenser positioneddownstream from the compressor to condense a refrigerant receivedtherefrom, and at least one evaporator positioned downstream of thecondenser and wrapped about the outer surface of the storage tank. Theevaporator includes a negative pitch coil configured to directrefrigerant flow from a position near the top of the storage tank to aposition near the bottom of the storage tank.

In another embodiment a chiller apparatus is provided. The chillerapparatus includes a storage tank defining an interior volume for thereceipt of liquid to be chilled. The storage tank includes a sidewallhaving an inner surface defining the interior volume and configured forcontact with the liquid. The storage tank has an outer surface notcontacting the liquid, and a bottom portion and a top portion. Thechiller apparatus includes a support plate disposed over the storagetank, and a sealed cooling system for circulating a refrigerant. Thecooling system includes a compressor mounted to the support plate forcompressing the refrigerant, a condenser positioned downstream from thecompressor on the support plate to condense the refrigerant receivedfrom the compressor, and at least one evaporator positioned downstreamof the condenser and wrapped about the outer surface of the sidewall.The evaporator includes a negative pitch coil configured to direct arefrigerant flow from the top portion of the storage tank toward thebottom portion of the storage tank.

These and other features, aspects and advantages of the presentinvention will become better understood with reference to the followingdescription and appended claims. The accompanying drawings, which areincorporated in and constitute a part of this specification, illustrateembodiments of the invention and, together with the description, serveto explain the principles of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

A full and enabling disclosure of the present invention, including thebest mode thereof, directed to one of ordinary skill in the art, is setforth in the specification, which makes reference to the appendedfigures, in which:

FIG. 1 provides a front elevation view of a water chiller apparatusaccording to an exemplary embodiment of the present subject matter;

FIG. 2 provides a plan view of a water chiller apparatus according to anexemplary embodiment of the present subject matter;

FIG. 3 provides a cross-sectional front view according to an exemplarywater chiller apparatus embodiment;

FIG. 4 provides a cross-sectional rear view of the exemplary waterchiller apparatus of FIG. 3;

FIG. 5 is a close-up cross-sectional side view an exemplary embodimentof a tank used in a water chiller apparatus of the present disclosure;

FIG. 6 is a close-up side view of an exemplary embodiment of the tankused in the exemplary water chiller apparatus of FIG. 5; and

FIG. 7 is an overhead cross-section view of another exemplary embodimentof a tank used in a water chiller apparatus of the present disclosure.

DETAILED DESCRIPTION OF THE INVENTION

Reference now will be made in detail to embodiments of the invention,one or more examples of which are illustrated in the drawings. Eachexample is provided by way of explanation of the invention, notlimitation of the invention. In fact, it will be apparent to thoseskilled in the art that various modifications and variations can be madein the present invention without departing from the scope or spirit ofthe invention. For instance, features illustrated or described as partof one embodiment can be used with another embodiment to yield a stillfurther embodiment. Thus, it is intended that the present inventioncovers such modifications and variations as come within the scope of theappended claims and their equivalents.

Turning to the figures, FIG. 1 provides a front elevation view of awater chiller apparatus 100 according to an exemplary embodiment of thepresent subject matter. Generally, the water chiller apparatus 100includes a casing 102 that extends between a top portion 104 and abottom portion 106 along a vertical direction V. Thus, water chillerapparatus 100 may be vertically oriented. The water chiller apparatus100 can be leveled, e.g., such that casing 102 is plumb in the verticaldirection V, in order to facilitate proper operation of the waterchiller apparatus 100.

As shown in FIGS. 1 and 2, the water chiller apparatus 100 also includesan inlet conduit 108 and an outlet conduit 110 that are both in fluidcommunication with a storage tank 112 within the casing 102. As anexample, warm water from a water source, e.g., a municipal water supplyor a well, enters the water chiller apparatus 100 through the inletconduit 108 from a top portion 116 of the tank. From the inlet conduit108, such warm water enters an interior volume 114 of the tank 112wherein the water is cooled to generate chilled water. Such chilledwater exits the water chiller apparatus 100 at the outlet conduit 110disposed at a bottom portion 118 of the tank 112 and, e.g., is suppliedto a medical device, drinking supply, or any other suitable feature. Aswill be understood by those skilled in the art and as used herein, theterm “water” includes purified water and solutions or mixturescontaining water and, e.g., elements (such as calcium, chlorine, andfluorine), salts, bacteria, nitrates, organics, and other chemicalcompounds or substances. Also, although water is described as anexemplary liquid, other suitable liquids may be supplied to the tank 112and chilled by the apparatus 100.

The tank 112, itself, includes a sidewall 120 having an inner surface122 defining the interior volume 114 and configured for contact with thewater to be chilled. An outer surface 124 of the sidewall 120 is definedopposite the inner surface 122 and does not contact the chilled liquid.The top or top portion 116 of the tank 112 and the bottom or bottomportion 118 of the tank 112 abut the sidewall 120 and enclose theinterior volume 114.

The water chiller apparatus 100 includes a sealed refrigerant coolingsystem 126 for cooling water stored or supplied to the tank 112.Generally, the sealed refrigerant cooling system 126 is configured tocirculate a refrigerant through or near the tank 112 to draw heattherefrom. Included in the sealed cooling system 126 are a compressor128, a condenser 130, a throttling device 132, and an evaporator 134. Asis generally understood, various conduits may be utilized to flow ordirect refrigerant between the various components of the sealed system126. The compressor 128, condenser 130, throttling device 132, andevaporator 134 may each be placed in fluid communication such thatrefrigerant generally flows downstream from the compressor 128 to therest of the system before returning to the compressor 128.

During operation, the compressor 128 motivates the refrigerant throughthe sealed cooling system 126 and acts to compress the refrigerantthrough the compressor 128, itself, increasing pressure and temperatureof the refrigerant such that the refrigerant becomes a superheatedvapor. As a superheated vapor, the refrigerant then passes to thecondenser 130, which may be positioned directly downstream from thecompressor 128. Within the condenser 130, the refrigerant is cooled asheat is drawn therefrom. The refrigerant subsequently exits thecondenser 130 as a saturated liquid and/or high quality liquid vapormixture. A fluid filter 136 may be provided downstream of the condenser130 to draw excessive moisture from the saturated liquid and/or highquality liquid vapor mixture. This high quality/saturated liquid vapormixture then travels through the throttling device 132, which isconfigured for regulating a flow rate of refrigerant therethrough. Thethrottling device 132 may generally expand the refrigerant, lowering therefrigerant's pressure and temperature. As a result, a cooled form ofthe refrigerant passes to the evaporator 134. While passing through theevaporator 134, the cooled refrigerant absorbs heat transferred to thestorage tank 112 from the water therein. Refrigerant ideally exits theevaporator 134 in a gasified vapor form before passing back to thecompressor 128. An accumulator 138 is provided in some embodiments andmay be configured to maintain gasification of the fluid flow as therefrigerant passes from the evaporator 134 to the compressor 128. Uponthe refrigerant reaching the compressor 128, the cycle repeats.

One or more tank temperature sensors 140 may be included and configuredfor measuring a temperature of water within the interior volume 114 ofthe storage tank 112. The tank temperature sensor 140 may be positionedat any suitable location within or on the storage tank 112. For example,the tank temperature sensor 140 may be positioned within the interiorvolume 114 of the storage tank 112 or disposed on the tank sidewall 120.The tank temperature sensor 140 may, moreover, be configured in operablecommunication with the compressor 128 to indicate when the compressor128 should be activated to circulate refrigerant. Such embodiments mayprovide indicate when additional or decreased cooling is needed. In someembodiments, multiple tank temperature sensors 140 may be included toprovide temperature measurements at multiple positions of the tank 112.

A controller 142 may be included and configured to control or regulatethe water chiller apparatus 100 and/or sealed cooling system 126.Controller 142 may be, for example, in operable communication with thesealed system 126 (such as the compressor 128, and/or other componentsthereof), and/or temperature sensor 140. Thus, controller 142 canselectively activate system 126 in order to cool water within theinterior volume 114 of the storage tank 112.

Controller 142 includes memory and one or more processing devices suchas microprocessors, CPUs or the like, such as general or special purposemicroprocessors operable to execute programming instructions ormicro-control code associated with operation of the water chillerapparatus 100. The memory can represent random access memory such asDRAM, or read only memory such as ROM or FLASH. The processor executesprogramming instructions stored in the memory. The memory can be aseparate component from the processor or can be included onboard withinthe processor. Alternatively, controller 142 may be constructed withoutusing a microprocessor, e.g., using a combination of discrete analogand/or digital logic circuitry (such as switches, amplifiers,integrators, comparators, flip-flops, AND gates, and the like) toperform control functionality instead of relying upon software.

As illustrated in FIGS. 3 and 4, one or more features of the waterchiller apparatus 100 may be attached to the tank 112 and mounted withinthe casing. Specific embodiments of the apparatus 100 include a supportplate 144 disposed over the storage tank 112, to which one or moresealed cooling system components may be mounted. For example, thecompressor 128 of an exemplary embodiment is mounted to the supportplate 144 and selectively positioned above the storage tank 112.

In optional or additional embodiments, the condenser 130 may be mountedto the support plate 144 above the tank 112. The condenser 130 may,moreover, include one or more air handler 160. The air handler 160 maybe positioned within casing on or adjacent a condenser body 162. Thus,when activated, the air handler 160 may direct a flow of air towards oracross the condenser 130, and assist with drawing heat from therefrigerant within the condenser body 162. The air handler 160 may beany suitable type of air handler, such as an axial or centrifugal fan.The condenser body 162 may be any suitable conduit structure fordirecting the refrigerant therethrough. One or more heat exchange finsmay extend therefrom and assist with heat transfer between the air andrefrigerant.

Throttling device 132 may be disposed above the tank 112 adjacent to thecondenser 130. The throttling device 132, itself, may be any suitablecomponents for generally expanding the refrigerant. For example, in someexemplary embodiments, throttling device 132 may be a Joule-Thomsonexpansion valve, also known as a “J-T valve.” In other exemplaryembodiments, throttling device 132 may be an ejector. In still otherexemplary embodiments, a capillary tube, fixed orifice, or othersuitable apparatus may be utilized as throttling device 132. In certainexemplary embodiments, throttling device 132 may be an electronicexpansion valve (EEV).

As shown, the evaporator 134 may include a negative pitch coil 166positioned generally downstream of the condenser 130 and/or directlydownstream of the throttling device 132. As illustrated, the coil 166 ofsome embodiments is wrapped about the outer surface 124 of the sidewall120, in direct contact thereto. In one exemplary embodiment, the coil166 is affixed to the storage tank 112 using a thermal paste thatimproves heat transfer. In another embodiment, the coil 166 is welded tothe tank 112. As shown in the exemplary embodiment in FIGS. 3 and 4, thecoil 166 may run along the outer surface 124 of the cylindrically-shapedsidewall 120 of the tank 112 in a helical pattern in the radialdirection R. Moreover, the negative pitch coil 166 may be configured todirect fluid flow substantially downward in the vertical direction V. Insuch embodiments, refrigerant flow is directed from a position near atop portion 116 of the storage tank 112 to a position near a bottomportion 118 of the storage tank 112.

In certain embodiments, the coil 166 has a negative pitch angle θdefined relative to the top 116 of the tank 112. As result, the negativepitch coil 166 may have an entry port 168 disposed vertically higherthan an exit port 170 when the tank 112 is vertically positioned. In anadditional or alternative embodiment, the negative pitch coil 166 has anegative pitch angle θ relative to the support plate 144 of the waterchiller apparatus 100. In such embodiments, the support plate 144 of thewater chiller apparatus 100 may define a horizontal plane which thenegative pitch coil 166 extends away from. The negative pitch coil 166may, advantageously, aid heat flow within the storage tank 112.Specifically, the negative pitch coil 166 is configured to conduct heatat a higher rate near a top portion 116 of the tank 112 than at a bottomportion 118 of the tank 112. The disparate heat transfers may therebygenerate a fluid flow of water within the storage tank 112. Chilledwater from the top portion 116 of the interior volume 114 can flowdownward toward the bottom portion 118 of the interior volume 114 asrelatively warm water flows upwards from the bottom portion 118.

As shown in FIGS. 3 and 4, the storage tank 112 may be positioned withinan outer jacket 172 of the casing 102. In such embodiments, the outerjacket 172 surrounds the tank 112 to create an annular space 174 betweenthe tank 112 and jacket 172. Insulation 176 may be provided withinannular space 174 to reduce the amount of heat transfer from theenvironment. As illustrated, the jacket 172 and insulation 176 mayfurther enclose the negative pitch coil 166, thereby increasing the heatabsorbed from the tank 112 to the coil 166. Insulation 176 is providedas foamed-in insulation for some embodiments, but other materials may beused as well.

In certain embodiments of the apparatus 100, it is desirable to increasethe surface area for contact between the negative pitch coil 166 and thestorage tank 112. Such an increase will provide increased heat transferbetween the coil 166 and the tank 112 for a given length of the coil166. Moreover, it can decrease the overall length of coil required totransfer heat from the tank 112 (and water therein) to the coil 166. Inadditional or alternative embodiments, it may be desirable to increasethe surface area and shape of the tank inner surface 122 in contact withwater within the interior volume 114. The increased surface area andchanges in shape advantageously improve the contact area with the waterand alter the film coefficient of convective heat transfer from the tankinner surface 122 to the water.

Accordingly, the storage tank 112 of some embodiments includes one ormore groove 178 formed along the outer surface 124 of thecylindrically-shaped sidewall 120 along an axial direction A, as shownin FIGS. 5 and 6. For example, a single continuous circumferentialgroove 178 may be formed about the sidewall 120 in a helical patternmatched to that of the negative pitch coil 166. As a result, when thewater chiller apparatus 100 is positioned vertically, the axialdirection may be parallel to the vertical direction V.

As further shown in FIGS. 5 and 6, one or more coil 166 from the coolingsystem 126 may fit into groove 178, thereby increased the surface areafor contact between the sidewall 120 and the coil 166 over a givenlength of coil. The groove 178 also appears on the inner surface 122 ofthe sidewall 120 and provides increased area for heat transfer withwater within the tank 112. Additionally, for some exemplary embodiments,the groove 178 has a circularly-shaped surface 179 to accommodate acircular profile of the coil 166. Specifically, the groove 178 mayaccommodate an outer coil diameter Di defined by the circular profile ofthe coil 166. However, in other embodiments the groove 178 may have asurface that is e.g., U-shaped, V-shaped, or square shaped.

The groove 178 in some embodiments has a depth De in radial direction Rthat is less than the outer diameter Di of the coil 166. In suchembodiments, the coil 166 extends beyond the outer surface 124 ofcylindrically-shaped sidewall 120 of the storage tank 112.Alternatively, the groove 178 may have a depth De that is greater thanthe outer coil diameter Di of the coil 166. The groove 178 may also havea width along the axial direction, A, approximately equal to the outerdiameter Di of the coil 166. It is envisioned that other configurationsmay be used as well.

In another exemplary embodiment, the storage tank 112 could be formedout of a process such that the interior surface of the tank 112 has aplurality of internal heat transfer features—e.g., ribs, fins, or thelike—that project into the tank 112 and extend longitudinally along theaxial direction A of the tank 112. For example, FIG. 7 provides across-sectional view of another exemplary embodiment of the tank 112where a plurality of T-shaped fins 180 are spaced apart about thecircumferential direction C of the tank 112 and extend along radialdirection R into the tank 112. Fins 180 also extend longitudinally alongthe axial direction A of the tank 112. Fins 180 could be formed, forexample, by welding or extruding the sidewall 120 with fins 180 inplace. Internal features such as fins 180 can, advantageously, increasethe rate of heat transfer from the water and improve the convective heattransfer film coefficient.

This written description uses examples to disclose the invention,including the best mode, and also to enable any person skilled in theart to practice the invention, including making and using any devices orsystems and performing any incorporated methods. The patentable scope ofthe invention is defined by the claims, and may include other examplesthat occur to those skilled in the art. Such other examples are intendedto be within the scope of the claims if they include structural elementsthat do not differ from the literal language of the claims, or if theyinclude equivalent structural elements with insubstantial differencesfrom the literal languages of the claims.

What is claimed is:
 1. A chiller apparatus for cooling a liquid,comprising: a storage tank for storing the liquid, the storage tankhaving a top and a bottom, the storage tank having an outer surface; anda refrigerant cooling system, comprising a compressor attached to thestorage tank, a condenser positioned downstream from the compressor tocondense a refrigerant received therefrom, and at least one evaporatorpositioned downstream of the condenser and wrapped about the outersurface of the storage tank, the evaporator including a negative pitchcoil configured to direct refrigerant flow from a position near the topof the storage tank to a position near the bottom of the storage tank.2. The chiller apparatus of claim 1, further comprising furthercomprising a thermal paste affixing the negative pitch coil to thestorage tank and enhancing heat transfer.
 3. The chiller apparatus ofclaim 1, wherein the storage tank includes an interior surface and aplurality of projections extending in a radial direction from theinterior surface of said tank to provide additional surface area forheat transfer with the liquid contained in the storage tank.
 4. Thechiller apparatus of claim 1, wherein the outer surface of the storagetank defines at least one circumferential groove, wherein the negativepitch coil is at least partially disposed in the circumferential groove.5. The chiller apparatus of claim 4, wherein the negative pitch coilincludes a circular profile defining an outer coil diameter.
 6. Thechiller apparatus of claim 5, wherein the groove includes a radial depththat is less than the outer coil diameter, and wherein the negativepitch coil extends above outer surface of the storage tank.
 7. Thechiller apparatus of claim 1, further comprising an outer jacketsurrounding the outer surface of the storage tank and enclosing thenegative pitch coil, the outer jacket defining an annular cavity betweenthe outer surface of the storage tank and the outer jacket.
 8. Thechiller apparatus of claim 7, further comprising an insulation materialdisposed within the annular cavity.
 9. The chiller apparatus of claim 1,wherein the negative pitch coil is wrapped around the storage tank in ahelical pattern having a negative pitch angle relative to the top of thestorage tank.
 10. A chiller apparatus, comprising: a storage tankdefining an interior volume for the receipt of liquid to be chilled, thestorage tank including a sidewall having an inner surface defining theinterior volume and configured for contact with the liquid, the storagetank having an outer surface not contacting the liquid, the storage tankhaving a bottom portion and a top portion; a support plate disposed overthe storage tank; and a sealed cooling system for circulating arefrigerant and comprising a compressor mounted to the support plate forcompressing the refrigerant, a condenser positioned downstream from thecompressor on the support plate to condense the refrigerant receivedfrom the compressor, and at least one evaporator positioned downstreamof the condenser and wrapped about the outer surface of the sidewall,the evaporator including a negative pitch coil configured to direct arefrigerant flow from the top portion of the storage tank toward thebottom portion of the storage tank.
 11. The chiller apparatus of claim10, further comprising a thermal paste affixing the negative pitch coilto the storage tank and enhancing heat transfer.
 12. The chillerapparatus of claim 10, wherein the inner surface of the sidewallincludes plurality of projections extending radially inward to provideadditional surface area for heat transfer with the liquid contained inthe storage tank.
 13. The chiller apparatus of claim 10, wherein theouter surface of the storage tank defines at least one circumferentialgroove, wherein the negative pitch coil is at least partially disposedin the circumferential groove.
 14. The chiller apparatus of claim 13,wherein the negative pitch coil includes a circular profile defining anouter coil diameter.
 15. The chiller apparatus of claim 14, wherein thegroove includes a radial depth that is less than the outer coildiameter, and wherein the negative pitch coil extends above the outersurface of the storage tank.
 16. The chiller apparatus of claim 10,further comprising an outer jacket surrounding the negative pitch coiland the sidewall of the storage tank, the outer jacket defining anannular cavity between the sidewall of the storage tank and the outerjacket.
 17. The chiller apparatus of claim 16, further comprising aninsulation material disposed within the annular cavity.
 18. The chillerapparatus of claim 10, wherein the negative pitch coil is wrapped aroundthe storage tank in a helical pattern having a negative pitch anglerelative to the support plate.
 19. The chiller apparatus of claim 10,further comprising a temperature sensor mounted to the storage tank inoperable communication with the compressor.
 20. The chiller apparatus ofclaim 10, wherein the storage tank includes an outlet conduit extendingfrom the interior volume at the bottom portion of the storage tank.